Nathaniel Fujita facing charges in death of Lauren Astley

A Wayland teen charged in connection with the death of his ex-girlfriend had been diagnosed with a depressive disorder weeks before the victim was found dead in a marshy area, his attorney said during opening statements Wednesday.

Nathaniel Fujita faces life in prison without parole if he's convicted in the death of his former girlfriend, Lauren Astley. Fujita’s lawyer will likely argue that the 20-year-old was insane at the time of Astley’s death.

They were both 18 and had just graduated from Wayland High School when prosecutors say Fujita stabbed and strangled Astley in July 2011 and then dumped her body in a marsh.

Prosecutors said Fujita’s actions were deliberate. They pointed to evidence of a specific search on his computer.

“Does water erase finger prints? I ask you when you hear that not only to think about the implications for what he did, but think about the implications for how his mind was working and what his intentions were,” prosecutor Lisa McGovern said.

Fujita’s attorney said his family has a history of mental disorders and that two family members suffer from schizophrenia.

"Nathaniel said he felt, at that pint, he had left his body," defense attorney William Sullivan said. "He didn't know what he was doing, and as a result this horrific act took place."

Both families have been at court hearings leading up to the trial week, still staying in touch despite the pain they've both been living through.

A maid who cleaned the home of former New England Patriots player Aaron Hernandez has testified at his murder trial that she saw him "messing with" the security camera in his basement the day after the killing.